In general, inkjet printing machines or printers include at least one printhead unit that ejects drops of liquid ink onto recording media or an imaging member for later transfer to media. Different types of ink can be used in inkjet printers. In one type of inkjet printer, phase change inks are used. Phase change inks remain in the solid phase at ambient temperature, but transition to a liquid phase at an elevated temperature. The printhead unit ejects molten ink supplied to the printhead onto media or an imaging member. Such printheads can generate temperatures of approximately 110 to 120 degrees Celsius. Once the ejected ink is on media, the ink droplets solidify. The printhead unit ejects ink from a plurality of inkjet nozzles, also known as ejectors.
Some inkjet printers use solid ink, which is also known as phase change ink. After the melted ink is on the media, the ink solidifies and then is warmed by a heater to soften the ink on the media. The softened ink is then fixed to the media by a pressurized nip formed by a spreader drum, which includes a hard surface or non-conformable surface, and pressure roller, which includes a compressible surface. An oil, also known as release agent, is deposited on the surface of the spreader drum and is spread by a metering device, typically a urethane metering blade. As the media with softened ink moves through the nip, the oil on the surface of the spreader drum prevents the compressed ink from offsetting to the spreader drum. After the media image has been compressed to fix the image to the media, the media can be directed to finishing equipment which applies a coating/varnish, such as a latex based coating, which provides a protective barrier to the deposited ink and which can also provide a selected finish, such as a glossy finish, to the final documents. The finishing equipment also cuts the continuous web into sheets.
One issue arising from printed materials is the ability to read or perceive indicia on documents in no-light or low-light conditions. The ability to place materials in the inks used or on the media are susceptible to wear or perseverance of the ability of the materials to enhance the readability of the indicia in no-light or low-light conditions. Consequently, systems or methods that enable the readability of indicia in no-light or low-light conditions are desirable.